Introduction to Rhubarb
Rhubarb is a medicinal herb with thick, yellow-brown root and stem. Also known as Tang Rhubarb, Tai Rhubarb, Tu Rhubarb, Yu Rhubarb, Zi Rhubarb, Bei Rhubarb, Da Huang, Ge Xi Gu Ne, Ye Rhubarb, Sour Grass, Huang Gu Luan Zi, Ku Rhubarb, North China Rhubarb, Qi Rhubarb, Zhuang Rhubarb.
Morphology Rhubarb is a perennial herbaceous plant, reaching over 1m in height. It has thick, yellow-brown roots. The stems are thick, erect, hairless, usually unbranched, and hollow. The basal leaves have long petioles; the leaf blades are ovate to ovate-round, 10-16cm long, with blunt tips, heart-shaped bases, wavy margins, and slightly hairy undersides; the stem leaves have short stalks or no stalks, with long ovate sheaths, dark brown, and clasping the stem. The inflorescence is a terminal panicle, with small, numerous, white-green flowers; the bracts are small, fleshy, and contain 3-5 small flowers; there is a joint below the middle of the flower stalk; the sepals are 6, ovate, in 2 whorls, with the outer whorl being thicker and smaller; stamens 9; ovary triangular-ovate, with 3 styles. The fruit is a thin-walled, winged achene, heart-shaped at the base, with persistent sepals. Blooms in summer.
Ecological Environment: Rhubarb grows on mountain slopes, crevices, and grasslands.
Distribution: Rhubarb is distributed in Northeast China, North China, and Hubei Province, among other places.
Identification: The roots and rhizomes of Rhubarb are irregularly cylindrical, with the upper part being thicker and the lower part slightly thinner, measuring 5-10cm in length and 1.5-5cm in diameter. The cork layer is often removed, and the surface is reddish-brown and yellow, without cross lines, with a firm and light texture. The cross-section has no star points, but has fine and straight reddish-brown rays. The fresh section is yellow to reddish-brown, and under ultraviolet light, it exhibits a blue-purple fluorescence. It has a faint odor and a bitter, astringent taste.
Chemical Composition: Rhubarb roots and rhizomes contain 1.11% total anthraquinone glycosides, with emodin and chrysophanol as the main forms of glycosides, accounting for 1.05%, and the free form accounting for 0.06%. It also contains edible rhubarb glycoside (rhapontin) and a large amount of tannins.
Properties and Flavors: Bitter; Cold in nature.
Meridians: Stomach; Large Intestine.
Usage and Dosage: Internal use: Decoction, 3-10g; or powdered. External use: Appropriate amount, powdered and applied; or used as a poultice.
Contraindications: "Medicinal Plants in the Desert Areas of China": Not suitable for use in those with weak constitution and during pregnancy and postpartum periods.
